INVESTIGATION OF MANY-BODY EFFECTS IN ONE-SIDE MODULATION-DOPED INP-INGAAS HETEROSTRUCTURE

A one-side modulation-doped quantum well of InGaAs lattice matched to InP has been used to investigate many-body effects in a quasi-two-dime nsional (2D) electron gas. The sample was grown by vapor levitation ep itaxy (VLE). Low-temperature photoluminescence (PL) measurements were carried out under different optical excitation intensities using 5145 Angstrom line from an argon ion laser. By increasing the laser intensi ty over five orders of magnitude a 13.2 meV blue shift in the PL line was observed to occur for a single asymmetric quantum well having a 2D electron gas density as low as 0.9 X 10(11) cm(-2). The observed blue shift is explained in terms of the reduction of both band bending (of the order of 1.8 meV) and many-body effects (of the order of 11.4 meV ) due to the reduction of the 2D electron gas density in the quantum w ell. (C) 1996 American lnstitute of Physics.